What is Aerobic?
The literal meaning of aerobic is “to live in air.” However, in 1968 Dr. Kenneth Cooper added an “s” to the word and created the familiar term aerobics, to encapsulate his research into the effects of exercise. His definition of aerobic activity focused on physical exercise producing improvements in the respiratory and circulatory systemsAerobic exercise is any activity that uses the larger muscles of the body — like the thigh muscles — and is sustained for at least ten minutes at a time. It is called aerobic because activity of this type requires the body to take in a higher-than-normal amount of oxygen. The benefits of aerobic exercise (also called cardio or cardiovascular exercise) are many, but most notable are the benefits to the cardiovascular and respiratory systems.Aerobic or cardio-respiratory exercises such as running, walking and swimming increase your heart rate and breathing rate because to do them, your body has to take in more oxygen. These types of exercises use your larger muscles and offer several benefits for your body, some of which directly affect your heart and lungs by making them stronger and more efficient. Not to be confused solely with jumping around to music wearing spandex, “aerobic training” encompasses all physical activity that affects the cardiopulmonary system.Potential benefits include optimum resting heart rate, a healthy level of blood pressure and lower risk of developing diabetes, or diseases of the heart and lungs. Aerobic benefits occur when the body is working between 40 percent and 80 percent of its age-related maximum heart rate. Maximum heart rate, known as MHR, is calculated as follows: 220 – age = MHR.
Benefits for Your Lungs
Cardio-respiratory exercises require that more oxygen flow through your body while you are working out. You breathe faster and more deeply, which strengthens the respiratory system. Your respiratory muscles, the diaphragm and the intercostals respond to training the same way any other muscles do. They become stronger and operate with greater ease over the course of time.
During aerobic exercise, the body uses more oxygen, and produces more carbon dioxide. This forces the lungs to work harder and to increase in capacity in order to handle the demands. After time, the lungs become more efficient and endurance increases, which causes more oxygen to enter the body’s cells upon each inhalation.
Benefits for Your Heart
The heart is the body’s hardest working muscle, and any aerobic exercise forces the heart to work harder . Over time, the heart becomes accustomed to the extra work, grows larger, and becomes more efficient. This efficiency carries over to all aspects of daily life.
Faster, deeper breathing increases your heart rate, giving your heart and blood vessels a workout. Because your heart is a muscle, exercising it strengthens your cardiovascular system so that it can pump more blood through your system without having to beat faster. During aerobic activity, the amount of blood pumped by the heart with each stroke increases, as does the number of beats the heart performs each minute. This is an involuntary reaction to satisfy the need for oxygenated blood and nutrients demanded by skeletal muscles. Because the heart is a muscle, it responds to training in the same way all muscles do, therefore progressive training will increase the volume of blood moved and power of each contraction.
Several studies have been completed which show that the more physically active a person is, the less likely he or she will suffer from coronary heart disease. Further, a person who engages in aerobic activity on a regular basis is less likely to be overweight or obese; will see a reduction in bad cholesterol levels; and will benefit from an increase in insulin sensitivity. All of these things benefit the cardiovascular system.
Even for heart attack survivors, aerobic exercise can condition your heart to help prevent future occurrences. The Centers for Disease Control and Prevention, or CDC, recommends that you engage in a cardio-respiratory activity for 2.5 hours per week
Oxygen in the lungs moves into the tiny blood vessels called capillaries and into the blood. It is then attracted to a chemical called hemoglobin. As this “oxygenated” blood travels around the body, it releases the oxygen into the cells of the muscles. Aerobic activity doesn’t increase the amount of hemoglobin in the body, but what it does is encourage the hemoglobin to release more of the oxygen it is carrying rather than returning it to the lungs to be breathed out.
Metabolism and Weight
The American Heart Association says “Good nutrition, controlling calorie intake and physical activity are the only way to maintain a healthy weight.” Obesity makes you more susceptible to cardiovascular disease. When you maintain a healthy weight, you ward off some of the factors that increase your risk for heart disease, such as high cholesterol and high blood pressure. Aerobic exercise burns calories and builds your large muscle groups so that they in turn contribute to your weight maintenance plans.
However, the calories burned while active are only part of the benefits. Dr. William Kraus of Duke University Medical Center established strong evidence that “long-term exercise training can lead to both short and long-term improvements in carbohydrate metabolism.” This means that a person who performs frequent aerobic exercise will process carbohydrates more effectively during and after exercise.
Lipoproteins carry cholesterol, a material present in your blood’s fats, through your body. High-density lipoproteins, also called HDL, bring cholesterol to your liver so your body can get rid of it, while low-density lipoproteins, or LDL, take cholesterol to your cells through the bloodstream. When cholesterol travels to your arteries, it can leave deposits that build up and create clogs that interfere with blood flow. According to the Mayo Clinic, cardio-respiratory exercises raise your high-density lipoproteins, and reduce your low-density lipoproteins. This reduces the buildup in your arteries and helps prevent ailments such as strokes.
The American Heart Association recommends that adults participate in 30 minutes of moderate-intensity cardio exercise five days a week, such as doing activities like walking fast, water aerobics, riding a bike on level ground and pushing a lawn mower, or performing more vigorous aerobic activity for 75 minutes a week. Exercise may be broken up into several short sessions during the day or done all at once. For maximum benefit, the activity should be sustained for at least ten minutes each time. Some examples of aerobic exercise are jogging, brisk walking, rowing, cycling, and swimming.
Anyone new to aerobic exercise should start slowly, and increase exercise intensity and duration in small increments. Feelings of dizziness, nausea, or light-headedness are indications to stop the activity immediately and seek medical attention. If you have any kind of medical history that includes heart, lung, or respiratory problems, ask your doctor’s advice before starting any new exercise program.
The cardiovascular system in the human body is made up of the heart and blood vessels, which are divided into arteries, veins and capillaries. The heart is responsible for pumping the blood throughout the blood vessels and is divided into four chambers, two of which are responsible for moving poorly oxygenated blood and two of which move highly oxygenated blood. Oxygenated blood, which is pumped through the body via the arteries, supplies the body’s tissues with oxygen that they need to live. Blood in the arteries is under high pressure; however, which could damage the tissue, so this oxygenated blood first needs to go to the capillaries, which are very small and low-pressure blood vessels that are responsible for supplying the oxygenated blood to the tissues. Once the capillaries have delivered their oxygen, they also absorb excess carbon dioxide into the blood and then deliver it to the veins, which then supply the blood back to the heart.
The respiratory system system is primarily comprised of the airways, the lungs and the structures (such as muscles) that help move air in and out of the lungs. The airway, which begins with the nose and mouth, continues down through the throat into the bronchi, which are small airways that eventually feed into the lungs, which are lined with cells called alveoli. The other part of the respiratory system is the muscles, such as the intercostals (muscles between the ribs) and the diaphragm, which cause the lungs to expand and contract. When the size of the lungs changes, so does the pressure inside, leading to air either coming in (inhalation) or being forced out (exhalation).
The cardiovascular and the respiratory system both work toward the same goal: getting oxygen to tissues and getting carbon dioxide out. The respiratory system is involved in supplying oxygen to the blood and removing carbon dioxide. When the heart receives blood that is low in oxygen and high in carbon dioxide, it pumps it to the lungs via the pulmonary arteries. When the lungs expand and get fresh air from the environment, oxygen is transferred (via the alveoli) into the low-oxygen blood, which also then sends some of its carbon dioxide back into the lungs. Now that this blood has fresh oxygen in it, it returns to the heart and the heart then pumps it throughout the body.
FUNCTION OF RESPIRATORY SYSTEM
If a hard run has ever left you short of breath, you are probably well aware of the respiratory system’s involvement in exercise. Under normal circumstances, the respiratory system function does not limit exercise performance and can obtain plenty of oxygen that the cardiovascular system transports to the working muscles. Nevertheless, exercise, particularly aerobic training, will improve respiratory system efficiency by increasing pulmonary ventilation, pulmonary diffusion and the relative amount of oxygen taken up by the muscles.
When you start to exercise, the muscles increase ATP production to fuel muscle contraction. To produce ATP, the muscles use oxygen and produce carbon dioxide, the latter of which needs to be removed. The respiratory system brings in oxygen needed by the working muscles and removes carbon dioxide produced. Pulmonary ventilation, or the process of moving air in and out of the lungs, increases immediately after starting to exercise to bring oxygen into the lungs. Oxygen diffuses from the lungs into the bloodstream in a process called pulmonary diffusion. The oxygen-rich blood travels through the bloodstream to the muscles, where it diffuses through the capillaries in a process known as capillary diffusion. Carbon dioxide from the muscles follows the reverse pathway: It diffuses from the muscles to the blood, where it is transported and diffused into the lungs, where it is expired into the outside air.
- Pulmonary Ventilation
Although exercise does not change the structure of the lung itself, your lungs and muscles will become more efficient at delivering oxygen to the muscles. Therefore, your pulmonary ventilation will be lower at a given submaximal exercise intensity. Your maximal pulmonary ventilation capacity, which is determined by the volume of air you can breathe in and out per breath and the rate at which you breathe, will increase with exercise. This is likely due to the strengthening of the respiratory muscles in the ribcage.
- Pulmonary Diffusion
Exercise does not increase pulmonary diffusion, or gas exchange in the lung, during submaximal exercise. However, pulmonary diffusion increases at maximal exercise. Training enhances blood flow to a greater proportion of your lungs, meaning that a larger area of your lungs will be involved in gas exchange. Additionally, greater pulmonary ventilation with training means more air is brought into the lungs, further increasing pulmonary diffusion.
- Muscle Capillary Diffusion
The amount of oxygen that is delivered to exercising muscle in the blood does not change with training. However, the amount of oxygen extracted from the blood into the muscle increases with exercise. First, the capacity for muscle fibers to use oxygen increases with exercise, meaning more oxygen will be extracted from the blood entering the muscle fiber. Second, the oxygen-rich blood is better at distributing itself away from the inactive body tissues and toward the active tissues. Additionally, exercise causes more muscle capillaries to form, meaning that a greater area of your muscle fibers are supplied with oxygen-rich blood and can take part in capillary diffusion.